I have two related tables: Groups and Clients. Clients belongs to Groups so I have a foreign key "group_id" that references the group a client belongs to.

I'm changing the Group id from an autoincrement to a UUID. So what I need is to generate a UUID for each Group and update the Clients table at once to reflect the changes and keep the records related.

Is there a way to do this with multiple-table update on MySQL?

Adding tables definitions for clarification.

CREATE TABLE `groups` (
  `id` char(36) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  `created` datetime DEFAULT NULL,
  `modified` datetime DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$


CREATE TABLE `clients` (
  `id` char(36) NOT NULL,
  `name` varchar(255) NOT NULL,
  `group_id` char(36) DEFAULT NULL,
  `active` tinyint(1) DEFAULT '1'
  PRIMARY KEY (`id`),
  KEY `fkgp` (`group_id`),
  CONSTRAINT `fkgp` FOREIGN KEY (`group_id`) REFERENCES `groups` (`id`) 
  ON DELETE NO ACTION ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8$$